CAMBRIDGE — The monthly schedule is church-like, with its parenting classes, guest speakers and small group meetings to hash out shared beliefs. But God isn't part of this Cambridge congregation.

Greg Epstein, the humanist chaplain at Harvard University, is building a God-free model of community that he hopes helps humanists increase in numbers and influence.

Epstein sees potential in research showing there are more people with no religion. In the latest American Religious Identification Survey, released this month, 15 percent of respondents in 2008 said they had no religion, compared to 8.2 percent in 1990. Epstein believes that group includes large numbers of people who are humanist, but have never identified themselves that way and can be reached.

At the same time, there is broader acceptance of those with no faith, as indicated by President Barack Obama's mention of "nonbelievers" in his inaugural address, Epstein said.

Definitions of humanism vary. Generally, humanists reject belief in the supernatural and are guided by reason, experience and compassion for others. Epstein defines the philosophy as a commitment to living ethical, personally fulfilling lives while serving the greater good.

Epstein wants to plant local humanist centers nationwide that perform many of the community-building functions of a church, only in service of the humanist creed. He will promote his idea as he tours the country to promote his book, "Good Without God," which is scheduled to be published by HarperCollins later this year. Epstein will receive assistance and funding from groups such as the American Humanist Association and the Secular Student Alliance, which have chapters they hope to strengthen and multiply.

"There are so many millions of people out there who basically share our views, that we've got room for everybody," Epstein said. "What we're doing here has got to grow even more."

Borrowing from religion Raised as a Reform Jew, Epstein studied Taoism and Buddhism before he became a humanist. He earned a master's degree in Judaic studies from the University of Michigan and a master's of theological studies from Harvard Divinity School. In 2005, he was ordained as a rabbi by the International Institute for Secular Humanistic Judaism. The movement says it combines reason, human experience, Jewish culture and ethical insights from Jewish tradition.

While many humanists reject anything that hints at organized religion, Epstein is freely borrowing from it — from the "small group" format familiar in evangelical churches to calling his group a "congregation."

Paul Kurtz, founder of the Council for Secular Humanism, disagrees with that approach, saying humanists are building secular communities that show people don't need religion to get together "in a joyful mood and do good works." But that's undermined when religious words are used to describe those communities.

"I don't think we should use the language of religion, that's very confusing," Kurtz said.

Though he supports Epstein, Fred Edwords of the American Humanist Association questions whether a large, untapped pool of potential humanists exists who would join congregations.

"This is a new mission field, if you will, but are those vineyards ripe for the picking?" Edwords said. "I haven't seen sufficient evidence of it."

Still, both men agree that more humanist communities are needed, for mutual support and to offset isolation humanists often feel.

Group support Jenni Acosta, a humanist from Newton who is part of the Harvard humanist parenting group, said the group gives her needed support, and shows her 6-year-old and 10-year-old daughters that other children are being raised the same way. Acosta, 36, said she deals with family and friends who challenge her on how she can raise her kids without the moral guidance a faith provides.

"I think it's reassuring to all of us to know that we're there for each other and there's other examples of people doing it and their kids seem to be turning out OK," Acosta said.

The Harvard chaplaincy also hosts "Humanist Small Group" biweekly Sunday brunch discussion and buys drinks at biweekly "Humanist Community Pub Nights." Last month, it hosted holiday-style celebrations around Charles Darwin's 200th birthday and is hosting a talk by humanist writer and director Joss Whedon of "Buffy the Vampire Slayer" fame.

Richard Lints, a professor of philosophical theology at Gordon-Conwell Theological Seminary, a prominent evangelical school in Hamilton said the humanist desire for greater community is understandable. He believes God "hard-wired" humans to need it.

But he said he doubts humanism can sustain itself in the local congregations Epstein envisions because community is not a natural part of humanism, where the individual is the ultimate source of meaning. If humanism becomes concerned with the "greater good," and a sort of natural moral order that implies, it starts to resemble religion and humanists will back away, he said.

"At the heart of the humanist project is deep individualism," Lints said. "It's always going to be difficult to sustain a real robust community."

To those who say it can't be done, Epstein points to his community at Harvard, and nonstop requests for more services, as a rebuttal. He believes humanists are responsible to make sure their community grows more.

"Salvation is here on earth," he said. "We have evolved over 14 billion years without purpose. Now we want purpose, we need to build it into our own lives."